Amphetamine is a stimulant that results in an increase in energy and activity, hyper-responsiveness to environmental stimuli, euphoria, and a number of physiological signs of hyperactivation. It was first synthesised in 1887 by a Romanian chemist named Lazăr Edeleanu, although no use for it was known until 1927 that pharmacologist Gordon Alles tested the chemical on himself. The D-stereoisomer of Amphetamine (dextroamphetamine) is conventionally found in medications that are used to treat mental and physical dysfunctions such as Attention Deficit/Hyperactivity Disorder (ADHD), Narcolepsy, and Chronic Fatigue Syndrome. Some of these medications (such as Adderall) also include the L-stereoisomer, levoamphetamine, in smaller amounts - however, levoamphetamine has less of an effect on dopamine levels than dextroamphetamine, and is thought to cause more negative side effects. The pharmacological mechanism of action is increasing the synaptic levels of biogenic amine neurotransmitters such as Norepinephrine, Dopamine, and Serotonin. Without a prescription, amphetamine is illegal in most countries, and when sold illegally for recreational use it is commonly known as "Speed".